1. Field of the Invention
The present invention relates to a resin composition comprising a catalyst precursor for electroless plating to form an electromagnetic wave shielding layer, methods for forming metal patterns using the resin composition, and metal patterns formed by the methods. More specifically, the present invention relates to a resin composition comprising a silver organic complex precursor as a catalyst precursor, methods for forming fine metal patterns using the resin composition, and metal patterns formed by the methods. The metal patterns of the present invention can be suitably used in the formation of films for shielding electromagnetic waves generated from the front surface of a variety of displays, including cathode ray tubes (CRTs), plasma display panels (PDPs), liquid crystal displays (LCDs) and electroluminescence (EL) displays, and in the wiring of flexible printed circuit boards.
2. Description of the Related Art
With the recent development and practical use of various types of displays, serious problems, such as hazards to human health and the malfunction of devices, have been encountered due to electromagnetic interference (EMI) noise generated from displays. In an attempt to solve these problems, an electrically conductive shielding film is formed on the front surface of a display to distort the propagation direction of electromagnetic waves generated from the display, followed by grounding to emit the electromagnetic waves.
Many methods are known to shield electromagnetic noise generated from the front surface of displays, including CRTs and PDPs, for example, by depositing a metal or metal oxide on a transparent substrate to form a conductive thin film. According to the exemplary method, however, since the conductive film must be formed as thin as possible to achieve transparency, the surface resistance of the conductive film is excessively increased, which makes it impossible to attain sufficient electromagnetic wave shielding effects.
In addition to these methods, methods have been reported wherein a conductive paste is patterned by a printing technique, such as screen printing or offset printing, and optionally the patterned paste is subjected to electroless plating to form an electromagnetic wave shielding film. However, there is a limitation in increasing the accuracy of printed circuits and there is a problem in that conductive materials infiltrate into irregular portions.
Further, some methods have been proposed wherein a metal layer is formed by photodevelopment and is subjected to electroplating or electroless plating to form an electromagnetic wave shielding film. However, drawbacks of these methods are that the photodevelopment requires the formation of several layers and the overall process is complicated. Further, methods have been reported wherein a metal catalyst is mixed with a photosensitive resin, the mixture is developed, followed by electroless plating and electroplating to form an electromagnetic wave shielding film. These methods, however, require the use of expensive palladium (Pd) as a catalyst and suggest no specific solution to avoid problems associated with the formation of a fine pattern and the electroless plating. Although the electroless plating is carried out to improve deposition characteristics, there is no specific approach to solve problems arising from detachment of the pattern in an aqueous solution of a strong base.